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The complex stacking disorder of Fe- and Ru-based 1,1′-(3,6-pyrazabolyl)metallocenes
No full text1,1′-(3,6-Pyrazabolyl)ferrocene [Fc(BHpz)₂] and the corresponding ruthenocene [Rc(BHpz)₂] crystallize as order–disorder (OD) structures with layers of Pma(m) symmetry. Since the m[100] reflection and the a[010] glide reflection planes of adjacent layers do not overlap, given one layer, the adjacent layer can be placed in four distinct, but geometrically equivalent, positions. There are accordingly four polytypes of a maximum degree of order (MDO). One analyzed Fc(BHpz)₂ crystal was composed of a mixture of the MDO₁ polytype in four distinct orientations and the MDO₃ polytype. A second crystal was essentially a single crystal of one out of two orientation of MDO₃. In two analyzed crystals of Rc(BHpz)₂, the MDO₁ polytype (P1) was the major polytype and was observed in four or two orientation states, respectively. Pronounced diffuse scattering is attributed to a complex disorder, which cannot be explained by simple growth models. One Rc(BHpz)₂ crystal features additional peaks in the diffraction pattern attributed to fragments of MDO₃
Estimation of Incidence Angles and Ranging Accuracy via Simulation of Full-Waveform LiDAR
No full textTopo-bathymetric LiDAR has become a standard 3D geodata acquisition technique in geosciences with a wide range of
applications in terrestrial and aquatic landscapes. In particular, the usage of short laser pulses with medium-sized footprints
for bathymetric applications has seen growing attention over the past decade. These LiDAR configurations have shown
higher relative changes in echo pulse width in relation to angle of incidence compared to standard topographic LiDAR
using more collimated near-infrared lasers. Although angle-dependent changes in amplitude have been well documented,
quantification of such a relation for the echo pulse width is still not entirely solved. By focusing on LiDAR with short
and broad pulses, we can therefore use the higher relative changes of such systems together with numerical simulations to
quantify the relationship between the echo pulse width and the angle of incidence. The simulation developed in this study
can be used to estimate neighborhood-independent angles of incidence from the recorded waveform, which enables the
angle of incidence calculation during waveform processing. These waveform-derived angles are comparable to established
methods based on the local point neighborhood, but generally display a higher variance leading to a mean absolute error
of about 10° when compared to neighborhood-based angles of incidence. Using the developed simulation, we also explore
angle-dependent shifts of the peak amplitude linked to potential ranging offsets. There, we were able to show ranging
offsets of up to 12 cm for strongly asymmetric laser pulses at angles of 80° and no offsets for symmetric laser pulses,
which provides new insights into the correctness of topo-bathymetric LiDAR systems. In conclusion, we present a detailed
simulation framework which can be used to estimate incidence angles and quantify potential ranging offsets
A conceptual architecture for AI-assisted Digital Twins in natural resource management
No full textThe management of natural resources is increasingly critical and challenging due to complex interactions among environmental, industrial, and societal processes. Traditional approaches often fail to integrate heterogeneous data, limiting predictive and decision-support capabilities. This study presents a conceptual architecture for an Artificial Intelligence (AI)-assisted Digital Twin (DT) of the Centre-Val de Loire region, designed to unify time-dependent multi-source data. Based on the ENVRI Reference Model, it covers Science, Information, Computational, Engineering, and Technology layers, defining standardized data exchange, communication protocols, and prototype functionalities. A proof of concept FIWARE implementation supports ingestion, monitoring and analytical services for piezometric and meteorological data, exemplified through groundwater dynamics in the Beauce aquifer. It integrates daily observations from 53 piezometric stations over more than five years, managing approximately 2.8 million records in a containerized environment.
Results show that the proposed DT architecture can enhance sustainability-oriented decision making, integrating heterogeneous data and predictive analyses while enabling collaboration across scientific and technical domains. Its modular design offers a replicable template for future AI-assisted environmental DTs, scalable to larger regions. Hence, this work illustrates how DTs can improve environmental monitoring and understanding, providing a pathway toward resilient, data-driven management of natural resources
Vacancy as a resource - causes, effects and revitalisation strategies for different types of space
No full textDie Auseinandersetzung mit dem Thema Leerstand als wachsendes Phänomen räumlicher Transformation beruht auf einer Vielzahl struktureller, wirtschaftlicher, planerischer und gesellschaftlicher Entwicklungen. Seine Aktualität manifestiert sich in tiefgreifenden Prozessen, die auf unterschiedlichen Maßstabsebenen wirksam sind und verdeutlichen, dass die Frage nach dem Umgang mit Raum, Bestand und Ressource zu einer zentralen Herausforderung im planerischen Diskurs geworden ist.Das Spannungsfeld zwischen neu erschlossenen Flächen und gleichzeitig ungenutztem Bestand zeigt die räumlichen Disparitäten in urbanen und ruralen Gebieten. Während an den Orts- und Stadträndern neue Bauflächen entstehen, verlieren die Zentren zunehmend an Funktion und Aufenthaltsqualität. Leerstand beeinflusst zudem das Erscheinungsbild und die atmosphärische Wahrnehmung in Städten und Dörfern und wirkt in baukultureller Dimension als Träger historischer Entwicklungen und des kollektiven Gedächtnisses. Vor diesem Hintergrund widmet sich die vorliegende Diplomarbeit der Betrachtung, Leerstand als Ressource zu begreifen - der Bezirk Baden, im niederösterreichischen Industrieviertel, dient dabei als Untersuchungsraum. Zwischen Wienerwald und Pannonischer Tiefebene gelegen, sind die räumlichen Dynamiken in der Region durch die Nähe zu Wien, durch Strukturwandel, Flächeninanspruchnahme und Wachstumsdruck geprägt.Ziel der Arbeit ist es, Ursachen, Auswirkungen, das historische Erbe und den regionalen Kontext zu analysieren und daraus ein Instrumentarium zu entwickeln, welches Gemeinden im Umgang mit un- und mindergenutzten Räumen unterstützt. Die drei Fallgemeinden Bad Vöslau, Tattendorf und Blumau-Neurißhof repräsentieren unterschiedliche Raumtypologien - urban, rural, post-industriell - und bilden die Grundlage für die Betrachtung von Raumstruktur, Gesellschaft und Baukultur.Methodisch basiert die Arbeit auf der Verknüpfung theoretischer, analytischer und kontextbezogener Verfahren. Der theoretische Teil verknüpft wissenschaftliche Grundlagen mit regionalen Analysen sowie den Ortsbegehungen und geht in einen praktischen Teil über, der durch Kartierungen und grafische Darstellungen ergänzt wird. Aus diesen Analysen entstehen die fünf Leitgedanken - Erfassen, Vermitteln, Aktivieren, Erhalten, Transformieren - die das entwickelte Instrumentarium strukturieren und Leerstand als räumliche, baukulturelle, soziale und atmosphärische Ressource begreifbar machen.Die Erkenntnisse zeigen, dass Leerstand stets im räumlichen und historischen Kontext zu betrachten ist, sich jedoch übergreifende Ansätze und Leitgedanken ableiten lassen. In Bad Vöslau steht die Reaktivierung der Kurkultur in ihren historischen Gebäuden im Vordergrund, in Tattendorf die Stärkung der dörflichen Identität und in Blumau-Neurißhof die Transformation des industriellen Erbes. Als gemeinsamer Ansatz wird die Stärkung der Ortskerne, die nachhaltige Innenentwicklung und die Bewusstseinsbildung für den Wert des Bestands verfolgt.Leerstand wird damit als Potenzial für räumliche, kulturelle und gesellschaftliche Entwicklungen verstanden, als Verbindung zwischen Vergangenheit und Zukunft, Funktionsverlust und Raumqualität, kultureller Identität und planerischem Handlungsbedarf.The examination of vacancy as a growing phenomenon of spatial transformation is based on a multitude of structural, economic, planning, and societal developments. Its relevance is reflected in profound processes operating across different scales, demonstrating that the question of how to deal with space, existing structures, and resources has become a central challenge within the planning discourse.The tension between newly developed areas and simultaneously unused building stock highlights spatial disparities in both urban and rural contexts. While new construction sites emerge on the edges of towns and cities, their centers are increasingly losing functions and quality of stay. Vacancy also affects the visual character and atmospheric perception of urban and rural settlements, acting as a mirror of historical developments and as a carrier of collective memory.Against this backdrop, the present thesis explores vacancy as a resource, focusing on the district of Baden, located in the industrial quarter of Lower Austria. Situated between the Vienna Woods and the Pannonian Basin, the region‘s spatial dynamics are shaped by proximity to Vienna, structural change, land consumption, and development pressure.The aim of the thesis is to analyze the causes, impacts, heritage, and regional context of vacancy in order to develop a set of instruments that can support municipalities in dealing with underused and unused building structures. The three selected case study municipalities - Bad Vöslau, Tattendorf, and Blumau-Neurißhof - represent different spatial typologies (urban, rural, and post-industrial) and provide the basis for a comparative examination of space, society, and building culture.Methodologically, the thesis combines theoretical, analytical and context-oriented approaches. The theoretical framework connects scientific foundations with regional analyses and on-site investigations and transitions into a practical part supported by mappings and graphic representations. From these analyses, five guiding principles emerge - Identify, Communicate, Activate, Preserve, Transform - which structure the proposed instrument and conceptualize vacancy as a spatial, architectural, social, and atmospheric resource. The findings reveal that vacancy as a resource must always be understood within its spatial and historical context, yet overarching approaches and guiding principles can be derived. In Bad Vöslau, the focus lies on reactivating the spa culture (Kurkultur) through its historic buildings, in Tattendorf, on strengthening village identity, and in Blumau-Neurißhof, on transforming the industrial heritage. As a shared approach, the thesis advocates for the revitalization of town centers, sustainable inner development, and raising awareness of the value of existing structures. Vacancy is thus understood as a potential for spatial, cultural, and societal development - a link between past and future, loss of function and spatial quality, cultural identity and planning action
Comparative Evaluation of Decay Characteristics of Commonly Used Genetic Faecal Markers Crassphage and Bacteroides in Complex River Water Microcosms
No full textComparative information on decay characteristics of genetic faecal markers including crAssphage is very limited for water resources, although PCR-based indicator-diagnostics are increasingly used worldwide. To our knowledge, we performed the first comparative microcosm experiments to assess the decay behaviour of commonly used qPCR-based genetic faecal markers (crAssphages, HF183/BacR287, BacHum) in a large European river. In addition, cultivation-based standards (E. coli, intestinal enterococci, Clostridium perfringens spores, somatic coliphages) were enumerated to allow for a cross-comparison between novel and established targets. River water was spiked with raw sewage from two combined municipal sewer systems and incubated at 8°C and 20°C for up to 66 days. The focus of the experimental work was put on genetic faecal markers. Two different filtration methods targeting either virus/phages and bacteria (using mixed cellulose esters, MCE) or solely bacteria (using polycarbonate filters, PC) were also evaluated. Results indicated biphasic decay for all targets (i.e., initial fast followed by secondary slow decay), with Bacteroides markers showing lower persistence under all conditions when compared to crAssphage. In addition, a tendency for higher long-term persistence of crAssphage based on MCE filtration as compared to PC filtration was observed. Finally, a meta-data analysis was conducted, comparing the results obtained here with those from recent case studies. This analysis further substantiated the comparatively higher persistence and lower decay of crAssphage relative to Bacteroides markers and established FIO, with the sole exception of C. perfringens spores
An Open-Path Eddy-Covariance Laser Spectrometer for Simultaneous Monitoring of CO₂, CH₄, and H₂O
No full textWe present E-CAHORS—a compact mid-infrared open-path diode-laser spectrometer designed for the simultaneous measurement of carbon dioxide, methane, and water vapor concentrations in the near-surface atmospheric layer. These measurements, combined with simultaneous data from a three-dimensional anemometer, can be used to determine fluxes using the eddy-covariance method. The instrument utilizes two interband cascade lasers operating at 2.78 µm and 3.24 µm within a novel four-pass M-shaped optical cell, which provides high signal power and long-term field operation without requiring active air sampling. Two detection techniques—tunable diode laser absorption spectroscopy (TDLAS) and a simplified wavelength modulation spectroscopy (sWMS)—were implemented and evaluated. Laboratory calibration demonstrated linear responses for all gases (R2 ≈ 0.999) and detection precisions at 10 Hz of 311 ppb for CO₂, 8.87 ppb for CH4, and 788 ppb for H₂O. Field tests conducted at a grassland site near Moscow showed strong correlations (R = 0.91 for CO₂ and H₂O, R = 0.74 for CH₄) with commercial LI-COR LI-7200 and LI-7700 analyzers. The TDLAS mode demonstrated lower noise and greater stability under outdoor conditions, while sWMS provided baseline-free spectra but was more sensitive to power fluctuations. E-CAHORS combines high precision, multi-species sensing capability with low power consumption (10 W) and a compact design (4.2 kg)
Robust control design to prevent unsteady bulging in continuous slab casters
No full textIn continuous casting of steel slabs, the ferrostatic pressure in the liquid core of the strand causes bending (also called bulging) of the strand shell between the guiding rolls. Unsteady bulging refers to a time-varying bending of the strand shell, leading to unwanted mold level fluctuations that can degrade the quality of the cast strand. Most mold level controller designs presented in the literature do not explicitly account for this disturbance due to the absence of suitable unsteady bulging models. As a result, these controllers often fail to sufficiently suppress unsteady bulging or even provoke it. This work presents a novel robust model-based controller design that systematically considers unsteady bulging by incorporating a control-oriented unsteady bulging model. Unlike previous approaches, the proposed method also accounts for variations in plant parameters to ensure robust suppression of unsteady bulging and consistent control performance across the entire range of operating conditions. The proposed controller is validated on industrial continuous slab casters, where it is now permanently used and achieves a significant reduction in mold level fluctuations
Soft and Stiff 3D Microstructures by Step‐Growth Photopolymerization Using a Single Photoresin and Multi‐Photon Laser Printing
No full textManufacturing three-dimensional (3D) microstructures with multi-material properties via two-photon 3D laser printing (2PLP) remains a significant challenge due to restrictions inherent to conventional chain-growth photoresins. Herein, an additive- and initiator-free resin formulation is introduced that allows for the printing of 3D microstructures with disparate mechanical properties via the step-growth photopolymerization-based self-dimerization of visible-light-active ortho-methylbenzaldehydes (oMBA) within a single fabrication step in 2PLP by altering the printing parameters (i.e., laser power, scan speed). It is established that the laser exposure dose (Dₑₓₚ) directly influences the material properties by varying the degree of crosslinking. While stiff materials with a Young's modulus above 1300 MPa at the higher edge of the Dₑₓₚ can be produced, soft materials with a Young's modulus of < 10 MPa at the lower edge of the Dₑₓₚ can also be fabricated. Thus, the herein pioneered resin offers a very broad material property window – spanning more than two orders of magnitude in Young's modulus – for multi-material printing via 2PLP, which is not achievable with conventional resins. The capabilities of the advanced resin are demonstrated by printing structures with hard and soft segments in a single fabrication step, visualizing their unique mechanical response to compression via in situ measurements
The Influence of Location Factors on C-ITS Effectiveness - A Simulation-Based Study of GLOSA Under Varying Conditions
No full textCooperative Intelligent Transport Systems (C-ITS) services, such as Green Light Optimal Speed Advisory (GLOSA), are technologies designed to address current challenges in the transport sector, particularly regarding traffic efficiency, safety, and sustainability. Beyond the technical configuration of C-ITS, the implementation context plays a crucial role in shaping the extent of their benefits. Understanding how these site-specific conditions influence C-ITS effectiveness is essential for optimizing deployments and ensuring that anticipated effects are achieved. This study proposes a methodology for analyzing and modeling the influence of site-specific factors on GLOSA performance. The effects of GLOSA on travel time, CO₂ emissions, and the number of stops were evaluated through traffic simulations conducted across multiple test sites. Key factors include (i) the number of lanes, (ii) the number of traffic signals, and (iii) the traffic flow. The simulation results show that GLOSA performance varies notably under different implementation conditions, highlighting the importance of context-dependent deployment strategies. To ensure robust and generalizable insights, multiple regression models were applied using k-fold cross-validation. Thereby, tree-based regression models such as gradient boosting and random forests demonstrated high accuracy and stable results. Additionally, cluster analyses were conducted to group locations with similar outcomes and identify patterns indicative of favorable implementation conditions. Sites characterized by higher traffic volumes, single-lanes, and several consecutive traffic lights demonstrated the greatest improvements in efficiency and emissions. Overall, this research supports developing context-dependent C-ITS implementation strategies and demonstrates how site-specific characteristics can guide deployment decisions
